A rare view of the epic ridge on the Chinese side of K2—so remote and difficult that most climbers tackle the Karakoram Range peak from the Pakistani side. Here, members of the 2011 expedition ferry equipment to the base of the 28,251-foot summit.

The swift current nearly swallows a two-hump Bactrian camel crossing the frigid stream that drains multiple glaciers in the Sarpo Laggo Valley of the Karakoram Range. The channel was the last but most difficult water barrier before arriving at Chinese Base Camp.

Bundled in their down suits, Ralf Dujmovits and Kaltenbrunner study the route up toward Camp IV and the beginning of the “death zone.” That is the point, above 8,000 meters, at which mountaineers who opt to climb without bottled oxygen face the limits of the human body. “What makes a difference in not having oxygen is your ability to fend off cold,” Dujmovits says. “You freeze yourself from the inside out, because you can’t burn enough fat to stay warm.”

Standing on the front points of her crampons, Kaltenbrunner climbs the steep rock-and-snow pitches up to Camp II. As part of extensive training before expeditions, she refines her balance by walking on a rope stretched between two apple trees.

Kaltenbrunner’s self-portrait, with Dujmovits behind her, shows the strain of grueling conditions. It was difficult to relax even on the flat terrain leading to Camp I, because the K2 North Glacier is mined with hidden crevasses.

Photograph by Ralf Dujmovits

With crampons, ice axes, and ropes they previously fixed, the climbers traverse west on the edge of the North Ridge. The route proved much steeper than they had anticipated.

On this day the weather is windy but improving. The fixed ropes buried under new snow, Kaltenbrunner presses on up to Camp III between fellow climbers Pivtsov and Załuski. “Many times I felt as if I were being carried along,” she says. “It was mystical—I was getting power from somewhere. It has happened to me a few times before, but the feeling was never so strong as on K2.”

A tiny pinprick of light emanates from the tent of the successful summit team (on the peak at center left), signaling their return to the bivouac site at 8,300 meters after 15 hours of climbing. Photographer Tommy Heinrich’s 14-minute exposure was made from Advanced Base Camp, more than two miles away.

Reunited after separating on the mountain, Kaltenbrunner and Dujmovits embrace at the depot above Advanced Base Camp. “The joy and relief that I felt when Ralf took me into his arms are almost impossible to describe,” Kaltenbrunner wrote on her website, which got 17 million hits on the day of the summit push. “My life’s dream has come true.”